Network+ Guide to Networks 5 th Edition

1. Network+ Guide to Networks5th Edition Chapter 15 Network Management

2. Objectives • Understand network management and the importance of documentation, baseline measurements, policies, and regulations to assess and maintain a network’s health • Manage a network’s performance using SNMP-based network management software, system and event logs, and traffic-shaping techniques • Identify the reasons for and elements of an asset management system • Plan and follow regular hardware and software maintenance routines

3. Fundamentals of Network Management

4. Fundamentals of Network Management • Network management • Assess, monitor, maintain all aspects of a network • Scope differs according to network’s size and importance • Several network management disciplines • All share same goals • Enhance efficiency and performance • Prevent costly downtime and loss • Predict problems before they occur

5. Documentation • Network management documentation types • Physical topology • Access method • Protocols • Devices • Operating systems • Applications • Configurations

6. Documentation (cont’d.) • Configuration management • Collection, storage, assessment of configuration documentation • Documenting all network aspects • Saves future work • Network diagrams • Graphical representations of network’s devices, connections • Use popular Cisco icons • Provide broad snapshots of network’s physical or logical topology

7. Figure 15-1 Network diagram using Cisco symbols Documentation (cont’d.)

8. Documentation (cont’d.) • Wiring schematic • Graphical representation of network’s wired infrastructure • Detailed form • Includes every wire necessary to interconnect network devices

9. Figure 15-2 Wiring schematic

10. Baseline Measurements • Baseline • Report of network’s current operation state • Baseline measurements • Network backbone utilization rate • Number of users logged on per day or per hour • Number of protocols running on network • Error statistics • Runts, collisions, jabbers, giants • Frequency of application use • Bandwidth usage

11. Figure 15-3 Baseline of daily network traffic Baseline Measurements (cont’d.)

12. CNN.com Traffic for 13 Years (link Ch 15a)

13. Baseline Measurements (cont’d.) • Compare future and past performance • Most critical network, user functions • More data provides more accuracy • Forecasting network traffic patterns • Difficult to predict users’ habits, new technology effects, changes in resources demand • Gathering baseline data • Software applications • Freeware • Expensive, customizable hardware and software • Determine use before selecting

14. Policies, Procedures, and Regulations • Rules limit chaos, confusion, downtime • Sound network management internal policies • Media installation and management (cables) • Network addressing policies • Resource sharing and naming conventions • Security-related policies • Troubleshooting procedures • Backup and disaster recovery procedures

15. Policies, Procedures, and Regulations (cont’d.) • State and federal regulations • CALEA (Communications Assistance for Law Enforcement Act) • Telecommunications carriers, equipment manufacturers must provide for surveillance capabilities • HIPAA (Health Insurance Portability and Accountability Act) • Protect medical records security and privacy • Many policies and procedures • Not laws • Best practices to prevent network problems

16. Cell Phone Surveillance • Link Ch 15b

17. CVS HIPAA Sanction • Link Ch 15c

18. For Schools: FERPA • Link Ch 15d

19. Fault and Performance Management

20. Fault and Performance Management • Assess network’s status on an ongoing basis • Performance management • Monitoring • How well links, devices keeping up with demands • Fault management • Detection • Signaling of device, link, component faults

21. Network Management Software • Enterprise-wide network management software • Accomplish fault, performance management • All use similar architecture • Polling • Collecting data from multiple networked devices at regular intervals • Agent • Software routine collecting information about device’s operation • Provides information to network management application

22. Network Management Software (cont’d.) • Managed device • Contains several objects to be managed • Processor, memory, hard disk, NIC, performance • MIB (Management Information Base) • Contains managed devices definition, data • SNMP (Simple Network Management Protocol) • Agents used to communicate managed device information • Part of TCP/IP suite: runs over UDP port 161 • Several ways to view and analyze data

23. Figure 15-4 Network management architecture Network Management Software (cont’d.)

24. Figure 15-5 Map showing network status Network Management Software (cont’d.)

25. How a Single Czech ISP Crippled the Entire Internet Normal During Czech Updates Link Ch 15e

26. Network Management Software (cont’d.) • Benefits • Flexible, sophisticated network management applications • Drawback • Challenging to configure and fine-tune • Be careful to collect only useful data • Common network management tool used on WANs • MRTG (Multi Router Traffic Grapher) • Command-line utility using SNMP to poll devices and collect data in log file; generates HTML-based views • Freely available

27. Figure 15-6 Graphs generated by MRTG Network Management Software (cont’d.)

28. Network Monitoring at CCSF

32. System and Event Logs • Log • Contains recorded conditions recognized by operating system • Event log • Windows-based computer log containing monitored device information • Event Viewer application • GUI to view Windows-based log information • System log • UNIX or Linux log

33. Figure 15-7 Event log on a workstation running Windows Vista System and Event Logs (cont’d.)

34. System and Event Logs (cont’d.) • Using logs for fault management • Requires thoughtful data filtering, sorting • Information collected does not point to problem

35. Traffic Shaping • Traffic shaping • Manipulating packet, data stream, connection characteristics • Manage type, amount of traffic traversing network • Goals • Assure timely delivery of most important traffic • Offer best possible performance for all users

36. Traffic Shaping (cont’d.) • Techniques • Delay less important traffic • Increasing priority of more important traffic • Traffic policing • Limit traffic volume flowing in, out of interface during specified time period • Limit momentary throughput rate for an interface • Not without controversy • Comcast discriminated against certain traffic types

37. Figure 15-8 Traffic volume before and after applying limits Traffic Shaping (cont’d.)

38. Comcast's Traffic Shaping • Links Ch 15 f, g, h

39. Phorm: Deep Packet Inspection • Links Ch 15i, j, k, l, m

40. Traffic Shaping (cont’d.) • Traffic prioritization • Treating more important traffic preferentially • Based on characteristics • Protocol • IP address • User group • DiffServ (Differentiated Services) flag or TOS (type of service) field in IP datagram • VLAN tag in Data Link layer frame • Service or application

41. Caching • Caching • Local storage of frequently needed files • Allows quick access • Web caching • Most common caching type, highly customizable • Web pages stored locally • On host or network, then delivered to requesters • ISP cache engine • Network device devoted to storage, frequently requested files delivery • Saves money, lowers WAN traffic

42. Asset Management

43. Asset Management • Identifying and tracking hardware and software • First step • Inventory each network node • Organization needs • Determine asset management tool selected • Benefits • Simplifies maintaining and upgrading network • Provides information about hardware and software costs and benefits

44. Change Management • Managing change while maintaining network efficiency, availability • Requires good planning • Common software and hardware changes • Installing patches to replacing network backbone • Several ways to approach changes

45. Software Changes • Keeping a system running optimally • Requires software upgrades • Software change types • Patches • Improvements, enhancements to particular software application code • Upgrades • Major changes to existing code • Revisions • Minor or major changes to existing code

46. Software Change Process • Research change benefits and effects • Determine how many systems to change • Notify administrators, help desk personnel, and users • Schedule the change off-hours • Back up the current system--have a rollback plan • Lock users out • Make the change and test it, roll back if necessary • Inform administrators, help desk personnel, and users of results • Document the change

47. Software Changes (cont’d.) • Patches • Correction, improvement, and enhancement to particular piece of software application • Changes part of application • Most code untouched • Vendors distribute at no charge • Often fix bugs • Not a software package replacement • Installed on top of existing software • Installation is similar to new software • Perform off-hours; test

48. Software Changes (cont’d.) • Patches (cont’d.) • Stay apprised of patches • Check vendor’s technical support Web site regularly • Subscribe to vendor mailing list • Patches may be bundled • Significant patches • Vendor notifications sent • Reported in trade journals

49. Software Changes (cont’d.) • Client upgrades • Software upgrade • Major change to software package’s existing code • Free • May substitute for vendors original code • Designed to add functionality and fix bugs • Client upgrades scope, purpose • Varies widely • Before applying upgrade • Read documentation

50. Software Changes (cont’d.) • Client upgrades (cont’d.) • May be transparent to users • May completely change appearance • Test on single workstation before general distribution • Prepare a reverse process • Installation methods • Workstation-by-workstation • Software distribution application • Plan carefully; inform users